KEEPING SCORE: Tokyo's Nikkei 225 was flat at 18,417.54 and South Korea's Kospi shed 0.5 percent to 2,136.85. Hong Kong's Hang Seng index fell 0.8 percent to 23,744.10 while the Shanghai Composite Index lost 1.2 percent to 3,159.89. Australia's S&P/ASX 200 was down 0.6 percent at 5,801.60. Stocks in Taiwan, Singapore and the Philippines also fell.

UK ELECTIONS: May called for an early general election in June, reversing her earlier stance, in hopes of securing a stronger parliamentary mandate for Britain's formal exit from the European Union. The pound climbed on expectations May might secure a better deal for Britain from EU thanks to moving the vote up from the next scheduled election in 2020. The announcement sent the pound higher but hammered the FTSE 100 index. The pound was trading at $1.2822, down from $1.2840 but still higher than the pre-announcement level.

ANALYST'S TAKE: "The surprise U.K. election has added to market nerves and volatility as traders assess the potential for increased geopolitical risk on several fronts," Ric Spooner, chief market analyst at CMC Markets, said in a commentary. "The outcome of the U.K. election now adds an element of short term uncertainty about how the Brexit negotiations will unfold."

OIL: U.S. crude oil futures lost 11 cents to $52.30 per barrel in electronic trading on the New York Mercantile Exchange. The contract lost 24 cents to close at $52.41 a barrel on Tuesday. Brent crude, used to price international oils, lost 15 cents to $54.74 per barrel in London.

CURRENCIES: The dollar rose to 108.58 yen from 108.42 yen. The euro fell to $1.0718 from $1.0731.